Bulk sheet handling equipment is used for sequentially separating large bulk quantities of sheet materials such as corrugated container blanks or other stacks of sheet materials into smaller, more manageable size "blocks" for further handling. Often the blocks need to be inverted for further processing.
Machinery developed for inverting sheet blocks, until advent of the present invention, has been found inadequate. Such machinery may spill the blocks of sheet material, leaving an untidy, unmanageable block after the inversion step. This is due in part to the fact that inversion requires a 180.degree. rotation of the blocks, and the older machinery was designed to complete the full rotation in one arcuate movement. The impetus of the block during rotation could cause the block to be propelled from the inversion device. This is especially true if the inversion device is to be operated at a rate commensurate with the operating speeds of the remaining handling machinery.
Another problem found with existing inversion machinery is that the discharge end of the downstream discharge conveyor (receiving the sheet blocks) must usually be adjustable to enable discharge of the blocks at different elevations. To accomplish such adjustment, the downstream discharge conveyor is usually pivoted at its infeed end. The prior inversion devices typically pivot on an axis different than the rotational axis of the sheet discharge conveyor. While one setting of the downstream discharge conveyor may properly coincide with the 180.degree. rotation of the inversion device, other settings will require similar adjustment of the inversion device to accommodate the new downstream discharge conveyor elevation. This causes complexity in adjustment of the inversion device rotation angle, and consequent down time while such adjustments are made.
A need has therefore been realized for an inversion device that will function reliably to consistently rotate sheet blocks without spilling the blocks onto the downstream discharge conveyor.
A need has also been realized for an inversion device that will operate at speeds commensurate with other associated handling machinery along the flow path of the sheet material.
A still further need has been recognized for an inversion device that will automatically accommodate itself to elevational adjustments of the downstream discharge conveyor without requiring complex, time consuming adjustment of either mechanism.